In the prior art there exists a self-propelled mower comprising a carrying vehicle and three work units. Said carrying vehicle is intended to support and to drive said work units. To do this, said carrying vehicle comprises, in particular, a chassis, an engine and a driver's cab. Said work units are, for their part, intended to cut a standing product such as grass, for example. This known self-propelled mower more specifically comprises a front work unit and two lateral work units. Viewed in a direction of forward travel, the front work unit is arranged at the front of said carrying vehicle. The lateral work units are arranged behind the front work unit, on either side of the area worked by the latter. Thus, this known self-propelled mower has a working width which may reach 9 meters. In the transport position, the front work unit is moved away from the ground by a substantially vertical translational movement. Said lateral work units are, for their part, brought close to a vertical mid-plane of said carrying vehicle by a pivoting movement. As a result, this known self-propelled mower can pass from a width of about 9 meters for work to a width of about 3 meters for transport. Such a reduction in width is necessary to allow the mower to travel on the public highway.